Telephone-transmitter.



0. E. "SGRIBNER.

TELEPHONE TRANSMITTER. AF LICAIIQH FILED JULY 97.1910,

1,050,304, Patented Jan. 14, 1913.

W/fnesses: o //1ven/0r:

C3 Char/es E. Scribner.

I Afly.

UNITED STATES PATENT OFFICE.

CHARLES E. SCRIBNER, 0F JERICHO, VERMONT, ASSIGNOR T0 WESTERN ELECTRICCOMPANY, OF NEW YORK, N. Y., A CORPORATION OF ILLINOIS.

TELEPHONE-TRANSMITTER.

Specification of Letters Patent.

Patented Jan. 14, 1913.

Application filed July 27, 1910. Serial No. 574,090.

I '0 all whom it may concern:

Be it known that I, CHARLES E. Somuxnu, citizen of the United States,residing at Jericho, in the county of Chittcnden and State of Vermont,have invented a certain new and useful Improvement in Telephone-Transmitters, of which the following is a full, clear, concise, andexact description.

This invention relates to telephone transmitters, its object being toprovide a simple and inexpensive structure which permits assembly of theparts in their proper relative positions without requiring great accuracy in the machining or shaping of the parts, or special devices foradjustment.

According to the invention, the diapbragm is loosely seated in a part ofthe frame of the instri'nncnt and is held in place by pressure exertedat its central point by a stud projecting from the front electrode, aspring suitably supported in the frame bearing against a shoulder of thestud and serving to hold the from electrode with yielding pressureagainst the diaphragm. In the preferred c nstruction this frontelectrode with its stud is a part of a granular button unit, the backelectrode thereof being provided with a rcarwardly extending stud andthe two electrodes being held together in a well known way by a thinmica diaphragm. In assembling the instrument the granular button unit isallowed to take a position which will give the proper pressure againstthe diaphragm, this pressure being automatically secured by the setpreviously given to the spring; then the back electrode is secured to abridge piece of the frame by mcans'of a set screw or other devicewhereby it is rigidly held in place. The diaphragm may be provided witha small indentation at its center and the front electrode stud may berounded or otherwise shaped so as to engage said indentation atsubstantially a point. The seat f r the diaphragm is preferably made alittle larger in diameter than the diaphragm so that the latter will notbind but will be free to take its natural position with respeet to thegranular button unit when the latter is secured to the bridge piece. The

diaphragm may also have a turned up oncumferential flange which isflattened at its extreme edge, thus providing an annularbearingsurface.At substantially the exact center of the diaphragm the front electrodemakes contact therewith.

The invention will be fully understood by reference to the accompanyingdrawing, in which Figure l is a side elevation with the easing insection of a telephone transmitter embodying the invention; Fig. 2 is anenlarged fragmentary view in section along the line 22 of Fig. 1; Figs.3 and 4 are detail views, Fig. 3 being an elevation of the bridge piecewith the granular button unit in place, and Fig. 4 a perspective view ofthe spring for engaging the stud of the front electrode.

In the drawing, the frame 1 of the transmitter is provided with theusual mouthiece '2 and bridge piece 3, a casing 26 servmg to cover theworking parts and to sup port the instrument. A diaphragm 4 is seated inthe frame 1 but insulated there from by a washer 5 which may be ofpaper, the diaphragm having a turned up circumferential flange 6flattened at its extreme edge. In the center of the diaphragm is a dc'iression 7 of a stud 8 secured to the front electrode 9 of a granularbutton unit 10, the radius of curvature of the stud and being slightlygreater than that of the depression, so that contact will be made at theperimeter of the depression. The stud 8 has a flange 27 forming ashoulder against. which the free upturned ends 28 of a spring 11 bear.This spring is held by but insulated from the bridge piece 3 by means ofscrews 12 and a tapped bar 13, a screw 14 being provided for connectinga wire to make electrical connection to the front electrode. The rearelectrode ot' the granular button 10 is provided with a stud 15 passingfreely through a hole in a tubular bolt 16. This bolt is of smallerdiameter than an opening 17 in the bridge piece '3, but is heldcentrally positioned in said opening and therefore out of contacttherewith by means of insulating button unit 10 is then inserted withits stud same with yielding pressure against the dianation with a frame.a diaphragm seated Washers 18, preferably of mica. These washers areseated as shown in depressions on either side of the bridge piece. Thebolt is held in place by a nut 19 and electrical connection to the backelectrode through the bolt is provided for by a terminal Washer 20 lyingunder the head of the bolt and held in place by it. A screw 24 isprovided for making the electrical connection to the rear electrode.

In assemblin the parts of this transmitter the tubular olt 16 and itsseveral Wastr ers are put in place and the nut 19 turned until the boltis held rigidly. The granular 15 lying loosely in place and the springll fastened in place with its free ends engaging the shoulder of thestud back of the rim 9. The diaphragm 4 is then placed loosely in itsseat against the paper washer 5 and the bridge iece is fastened securelyto the frame 1 wlth the end of the front electrode stud 8 engaging thedepression 7 at the center of the diaphragm. At this time the spring 11Will give somewhat, but willcxert the proper pressure against thediaphragmand the position of the dia phragm in its seat Will be adjustedto conform to any slight irregularities in the for mation of the bridgeand the position of the granular button therein. At the. same time thestud 15 of the back electrode Will be pushed backwardly and assume itsproper position in the bolt opening. Finally the back electrode isrigidly held in place by the set screw 25. By this construction and arrangement the several parts will assume their natural positions withoutdanger of any stress on the frail mica diaphragm 29 of the granularbutton unit. While the dampening pressure is automatically regulated bythe set of a single spring and is exerted perpendicular to and at theexact center of support of the diaphragm and therefore Without danger ofdistorting its shape.

Having thus described my invention,w11at I claim is:

1. In a telephone transmitter, the combination With a frame, a diaphragmseated therein and a bridge of said frame over the diaphragm, of anelectrode having a stud extending toward and adapted to loosely en gageonly a central point in said diaphragm. a spring engaging said stud tohold the phragm and thus to retain the diaphragm in its seat, anopposing electrode, and adjustable means for holding thesame to saidbridge.

2. In a telephone transmitter, the combr therein and a bridge over saiddiaphragm. of an electrode hating a shouldered stud. a spring pressingagainst the shoulder of said i stud to hold the same in yielding contactwith a central point in the diaphragm, an opposing electrode, andadjustable means for holding the same to said bridge.

$3. In a telephone transmitter, the combination with a frame. adiaphragm seated freely therein. and a bridge over said dia )hragm, ofan electrode having a central stud rounded at its end and provided witha shoulder, a spring pressing against the shoulder of said stud to holdthe same in yielding contact- With a central depression in thediaphragm, an opposing electrode, and adjustable means for holding thesame to said bridge.

4. In a telephone transmitter, the combination with a frame, a diaphragmseated freely therein and a bridge over said diaphragm, of a frontelectrode having a stud extending toward and adapted to loosely engageonly a central point in said diaphragm, a spring carried by said bridgeand having its free end bearing against said stud to hold the same inyielding contact against a central. point. in the diaphragm and thus tohold the diaphragm securely in its seat, a back electrode, andadjustable means for holding the same to said bridge.

5:. In a. telephone transmitter, the combination with a frame. adiaphragm seated therein and the bridge of the frame over saiddiaphragm, of a granular button unit comprising two electrodes and athin inshlating diaphragm. one of said electrodes having a studextending toward and adapted to loosely engage a central point in thefirst mentioned diaphragm, and the other of said electrodes ha ring astud extending through an opening in said bridge, a sprin engaging thefirst mentioned stud to 101d the same with yielding pressure against thediaphragm. and adjustable means for fastening the last mentioned stud inthe opening of said bridge.

(3. In a telephone transmitter. the combi nation with a frame, of adiaphragm loosely seated therein and having a central depression, abridge of the frame over said diaphragm, an electrode having a studextending toward and adapted to engage only the depression in saiddiaphragm, a spring engaging said stud to hold said electrode in placewith yielding pressure against the diaphragm, an opposing electrode, andadjustable means for holding the same to said bridge. 7 i

7. In combination, a transmitter frame, a diaphragm loosely seated insaid frame, said diaphragm being of less diameter than its seatingsurface and having a central depres- Fsion. a front electrode, a studprojecting fr m said electrode and engaging only said depression. and aspring engaging said stud.

S. In combination, a transmitter frame hav ng a flat b a ing Surface, adiaphragm against the diaphragm and the diaphragmv loosely seatedtherein, the diameter of the against the flat surface of the frame. 10diaphragm being less than that of the flat In Witness whereof, I,hereunto subscribe surface, said dlaphragm being provided my name this26 dav of July A. D., 1910.

with a central depression, an electrode en- CHARLES E. SGRIBNER. gagingthe diaphragm only at said depres Witnesses: sion, and a spring mountedon the frame and MORGAN WASI-IBURN, J12,

engaging said electrode to hold the same. F. P. MCINTOSH.

